Method of forming a micromechanical system containing a microfluidic lubricant channel

Abstract

Embodiments of the present invention generally relate to a electromechanical device that has an improved usable lifetime due to the presence of one or more channels that contain and deliver a lubricant material that can reduce the likelihood of stiction occurring between the various moving parts of the device. Embodiments of the present invention also generally include an enclosed device package, and a method of forming the enclosed device package, that has one or more lubricant containing and/or transporting channels that that deliver lubricant material to a device disposed within the enclosed device package. Each lubricant containing channel acts as a ready supply of “fresh” lubricant to prevent stiction from occurring between interacting components of the device disposed within the enclosed region of the device package. The ready supply of “fresh” lubricants may also be used to replenish damaged lubricants (worn-off, broken down, etc) at the contacting surfaces where stiction generally occurs.

1. A process for forming a plurality of sealed micromechanical device packages, each having a fluid channel, the process comprising:
 forming a lid having a first bonding surface; 
 forming an interposer having a second bonding surface and a plurality of through holes formed therein, wherein an interior surface is formed in the interposer by each of the through holes; 
 forming a plurality of micromechanical device assemblies on a surface of a substrate, wherein the micromechanical device assemblies each include a moveable component having a first contact surface that interacts with a second contact surface during device operation; 
 bonding the first bonding surface to the second bonding surface using a first bonding process to form a lid assembly, wherein a plurality of recessed regions are formed between the interior surfaces of the interposer and a surface of the lid assembly; 
 positioning and aligning the plurality of formed recessed regions relative to the plurality of micromechanical device assemblies formed on the substrate so that each of the micromechanical device assemblies can be placed within a recessed region; 
 bonding the lid assembly to the substrate using a second bonding process to form a plurality of processing regions formed between the recessed regions and a surface of the substrate, wherein one or more of the micromechanical assemblies are positioned within the processing regions; 
 forming a plurality of fluid channels in the interposer, lid, or substrate so that a portion of at least one fluid channel is in communication with each of the processing regions; 
 dicing the substrate and the lid assembly to form a plurality of sealed micromechanical device packages, wherein each of the sealed micromechanical device packages comprise a portion of the substrate, a portion of the lid assembly and one or more of the micromechanical device assemblies positioned within the processing region, and wherein said at least one fluid channel formed in each of the sealed micromechanical device packages that is in communication with the processing region is not exposed to an exterior of said each of the sealed micromechanical device packages; 
 removing material from a surface of at least one of the sealed micromechanical device packages to expose a portion of a fluid channel formed in the interposer, lid or substrate; 
 disposing a lubricant in the fluid channel through the exposed portion of the fluid channel; and 
 sealing the exposed portion of the fluid channel. 
 
   
   
     2. The process of  claim 1 , wherein the moveable component comprises a mirror. 
   
   
     3. The process of  claim 1 , further comprising forming one or more obstructions within each of the plurality of fluid channels, wherein the obstructions are adapted to act as a particle sieve. 
   
   
     4. The process of  claim 1 , further comprising forming two or more filters within the each of the plurality of fluid channels, wherein the filters each comprise one or more obstructions that are positioned within the fluid channel. 
   
   
     5. The process of  claim 1 , wherein the liquid lubricant is selected from a group consisting of perfluorinated polyethers, dichlordimethylsilane, octadecyltrichlorsilane, perfluoroctyltrichlorsilane, perfluorodecyl-trichlorosilane, and fluoroalkylsilane. 
   
   
     6. The process of  claim 1 , wherein each of the fluid channels that is formed in the interposer, lid, or substrate is configured to exert a capillary force on a lubricant that is to be disposed therein. 
   
   
     7. The process of  claim 1 , wherein each of the fluid channels that is formed in the interposer, lid, or substrate has a width that is between about 10 μm and about 800 μm and a depth that is between about 10 μm and about 200 μm. 
   
   
     8. The process of  claim 1 , wherein each of the fluid channels that is formed in the interposer, lid, or substrate has a volume that is between about 0.1 nI and about 1000 nI.